First consider the expression for: Take the product of $6$ and $x$ and add $9$. Now select the answer that matches the following: The sum of $1$ and the product of $4$ and that expression.
Explanation: Let's break this problem into smaller and easier pieces. What is the product of $6$ and $x$ $6 \times x = \color{orange}{6x}$ What does adding $9$ to $6x$ do? $6x$ $ + 9$ What is the quantity of $4$ times that expression $4 \times (6x + 9) = \color{orange}{4(6x+9)}$ What is the sum of $1$ and $\color{orange}{4(6x+9)}$ $4(6x+9)$ $ + 1$ So the entire expression we're considering can be written as $4(6x+9)+1$.